The purpose of this proposal is to understand the role of zipcode-binding protein ZBP1 in the mechanism of mRNA localization. Over the last project period, we have identified and characterized the role of this protein in localizing -actin mRNA to the periphery of cells where it is involved in synthesizing proteins important for neuronal growth and cell motility. This protein binds to the zipcode of mRNA and transduces nucleic acid sequences into cellular spatial information. Surprisingly, this protein is at a central point in the cellular basis of disease, we have found it to be a metastasis suppressor and play a role in neuronal pathology and even in behavior. We hypothesize that ZBP1 is carrying a group of mRNAs to focal adhesion complexes or sites of cell-cell contact and this regulates intercellular or cell-substrate interactions. Our experimental focus in this work is to identify the RNA and protein binding partners of ZBP1; in particular using TIRF. We will then characterize its crystal structure and determine how it interacts with specific proteins to move mRNAs and allow their expression. Finally, we will visualize these processes in living cells from mice carrying a modified -actin mRNA and in a knock-out of ZBP1. PUBLIC HEALTH RELEVANCE: We have discovered a protein that controls how and where other proteins are made in the cell. We have found that this protein is implicated in suppressing cancer metastasis and maintaining normal nerve function. We are investigating how this protein works to localize protein synthesis in specific regions of the cell by using a super-sensitive microscope to watch the process occur in living cells and tissues from genetically engineered mice.